remove QID import style (#2005)

* remove QID import style

* remove QID import style

plugins/org.yakindu.sct.model.stext/src/org/yakindu/sct/model/stext/SText.xtext

@@ -58,7 +58,7 @@ InternalScopeDeclaration returns types::Declaration:
 	EventDefinition | VariableDefinition | OperationDefinition | TypeAliasDefinition
 ;
 ImportScope:
-	 {ImportScope} 'import' ':' (imports+=QID | imports+=STRING)*;
+	 {ImportScope} 'import' ':' imports+=STRING*;
 
 EventDefinition:
 	(direction=Direction)? 'event' name=XID (':' typeSpecifier=TypeSpecifier)?;

test-plugins/org.yakindu.sct.model.stext.test/src/org/yakindu/sct/model/stext/test/validation/STextJavaValidatorTest.java

@@ -840,7 +840,7 @@ public class STextJavaValidatorTest extends AbstractSTextValidationTest implemen
 
 	@Test
 	public void checkImportExists() {
-		Scope context = (Scope) parseExpression("import: does.not.exist", ImportScope.class.getSimpleName());
+		Scope context = (Scope) parseExpression("import: \"does.not.exist\"", ImportScope.class.getSimpleName());
 		AssertableDiagnostics validationResult = tester.validate(context);
 		validationResult.assertErrorContains(String.format(STextValidationMessages.IMPORT_NOT_RESOLVED_MSG,"does.not.exist"));
 	}